This invention relates to on-premise data communication systems.
In recent years, the fast proliferation of Personal Computers (PC) and associated peripherals in workplace have created a need for communication among Computing Devices (CD). Local Area Network (LAN) has been developed to meet such demand. To link among CDs located at distance, Gateway technology was deployed to funnel messages between LANs through long distance communication facilities, generically referred to as Wide Area Network (WAN).
To communicate with one another, each CD on a LAN uses an Network Interface Card (NIC) to access a common transmission medium. Each NIC has an unique factory preset identity for addressing one another in transmitting data packets.
To coordinate these activities among multiple CDs, conventions have been established in LAN environment to transmit messages that broadcast the address, identity and status, etc. of each computing device.
To access other LANS, a Gateway CD uses a Modem as the physical interface to the WAN. Depending on the type of WAN in use, this modem could range from conventional analog telephone line type (e.g. V.90 56K bps), xDSL (Digital Subscriber Loop), ISDN (Integrated Service Digital Network), Cable, fiber, Radio to Satellite, etc. Once a connection is made, a Client CD conducts its transactions with a remote CD through Gateway via LAN facility. Thus, a Gateway assumes two personalities. It is a node in a LAN, as well as a focal point for WAN traffic.
To establish a WAN connection, a Client would request such service from Gateway by sending message through LAN with Gateway""s address as destination header. After the connection is made by the Gateway, a Client would conduct communication using data packets made of the remote CD""s address plus an overhead header of the Gateway""s address, so that the messages will funnel through the Gateway. The most common application of this kind is to simultaneously access Internet from multiple CDs. The process of sharing the same WAN link is handled by a special class of software known as Internet Sharing Software (ISS).
Originally, coaxial cable were used as the physical connection medium for LANs. With improved transmission technology, twisted pair cables can now be used. Even though both have been deployed widely in business, the requirement of installing such specific wiring is not inducive in residential settings.
The lately available Home Phoneline Networking (HPNxe2x80x94U.S. Pat. No. 5,696,790) technology capable of transmitting high speed digital signals over a single pair of traditional on-premise telephone wiring has made residential level LAN service feasible. In particular, there is a great potential for applying this technology to SOHO (Small Office Home Office) settings. By utilizing the existing on-premise telephone wiring as transmission medium, a LAN can be easily established among data terminals equipped with interface modules based on HPN technology. With SOHO CDs networked, their original individualized WAN access can be consolidated by designating one CD as the Gateway.
Because LAN technology was originally developed for corporations, its operation principles do not suit SOHO situations very well. For example, the Gateway of a LAN is a communication focal point in a business. Thus, it is expected to operate continuously. Much emphasis has been spent to well equip it for maintaining a full-time, un-interrupted service. In the SOHO environment, a CD may be designated as a Gateway but it is just for the sake of conforming to the LAN operation convention and terminology for WAN access. Most components on a SOHO Gateway may be the same as any other Client CDs.
With a LAN, certain facilities originally installed on individual Clients are no longer used. This is economical in terms of simultaneous WAN access and peripheral device sharing. However, in SOHO and residential settings, CDs are powered on only when they are needed. Thus, the Gateway may not be turned on when a Client needs to access the WAN. The extra step of turning on the Gateway for such occasions puts a negative impact on the benefits of setting up a LAN for resources sharing. This is especially irritating for Clients originally had the same WAN access capability as the Gateway. For example, most new PCs are factory equipped with V.90 (56K bps) modems for independent WAN access. It is hard to explain to an user that, after the installation of a LAN, a Client PC has, all of a sudden, lost its ability to access the WAN, unless another PC (the Gateway) is also turned on.
It is therefore the objectives of this invention to present a methodology of enhancing the operation characteristics of a Client in a LAN when the service from the designated Gateway is not available.
Another goal of this invention is to avoid disrupting an active WAN connection, when a computing device capable of providing Gateway service joins the network.
Yet another objective of this disclosure is to maximize the opportunity for the originally designated Gateway, which is equipped equal or better than the Clients, to resume its Gateway responsibility.
This document discloses a novel local communication system operation protocol that utilizes the LAN status information to enhance the xe2x80x9cartificial intelligencexe2x80x9d of networked computing devices. That is, the Clients normally rely on the Gateway for WAN access, if it is active. But, any Client with WAN access capability can activate its independent facility if the Gateway is not ready to provide the service. Furthermore, if a WAN connection has already been established, other Clients should be configured to utilize this Client as WAN access point. Even the Gateway would join the network as a Client. Lastly, whenever possible, the Gateway will take over the control of WAN access, so that the predefined best possible service configuration is available to all terminals.
More specifically,
A. If a LAN has a Gateway ready to provide WAN access service, all other computing devices should stay in their predefined Client mode.
B. If no Gateway is active to provide WAN access service, each Client having WAN access facility will configure itself to be ready to use its own WAN access capability.
C. While one of the Clients, in the absence of the Gateway, has established a WAN connection, the other Clients will configure themselves to utilize this connection, when needed.
D. If the Gateway is powered on after a Client has already established a WAN connection, it should temporarily confine itself to be a Client. That is, the Gateway will access WAN through the Client already connected to WAN, thus avoiding to disturb the ongoing traffic.
E. Whenever the active WAN link is disconnected, the predefined Gateway would take over the control of the LAN and resume the responsibility of WAN access service.
F. Upon power down, any temporary Gateway/Client designations of the current session will be cancelled, such that the predefined network configuration will be attempted upon the next power on.
One basic application for this methodology is to establish a coordinated LAN operation for accessing WAN in SOHO environment where the flexibilities of establishing a shared access configuration as well as operating each CD standing-alone are equally important.
One of the advantages of the present invention is that a predefined configuration is maintained as much as possible to maximize the system performance. On the other hand, the proposed alternate link satisfies the Client""s temporary needs, although such link may have lower service grade than that provided by the predefined Gateway.